The present invention relates to a microphone unit and a method of manufacturing the same.
A technique for downsizing a sound input device has become important with a reduction in size of electronic equipment. For instance, a technique for manufacturing capacitor microphones on a silicon substrate has been developed as such a technique (see; for instance, Japanese Patent Publication No. 2006-157863 A).
For instance, a differential microphone that generates a differential signal showing a difference between voltage signals from two microphones and that utilizes the thus-generated differential signal has hitherto been known as a microphone having directivity. In particular, in order to realize a differential microphone having a superior high-frequency characteristic, it is important to match acoustic impedance of one microphone to that of the other microphone.